Electromagnetic relay assembly for indicating unbalance of a vibrating machine



1964 s. A. FINDLEY ETAL ELECTROMAGNETIC RELAY ASSEMBLY FOR INDICATING UNBALANCE OF A VIBRATING MACHINE Filed Jan. 4, 1962 INVENTORS GA/vua fizz/amaze fi/v040 BYMA/AM 6. 041.

z 5 4M I I TTORNEYS Patented New. 24, 19%4 The present invention relates to an improved relay assembly, and has particular reference to assemblies for indicating a condition of dynamic unbalance in washing machines.

When an unbalanced load exists in the basket of a washing machine, the basket may develop an eccentric motion about its axis which, if not corrected, could cause severe damage. The present invention provides a system which detects such conditions of unbalance, deenergizes the machine, and gives an audible signal to the operator that such. condition exists.

An object of the present invention is to provide an improved relay assembly for detecting conditions of dynamic unbalance.

Still another object of the present invention is to provide an improved relay assembly for deenergizing a washing machine or the like when conditions of dynamic unbalance eXist, and providing a signal to the operator.

Still another object of the invention is to provide an improved relay assembly which is simple and economical in construction.

A further description of the present invention will he made in conjunction with the attached sheet of drawings which illustrates a preferred embodiment of the invention.

in the drawings:

FIGURE 1 is a fragmentary view in elevation, and partly in cross section, illustrating the manner in which the relay assembly of the present invention may be incorporated into a washing machine structure;

FIGURE 2 is a view in elevation of the relay assembly, partly broken away, illustrating the position of the elements when the washing machine is in its normal running condition;

PTGURE 3 is aview similar to FIGURE 2 but illustrating the position of the elements when the relay is closed, thereby deenergizing the washing machine; and

FIGURE 4 is a schematic diagram of the electrical circuit of the relay.

As shown on the drawings:

In FEGURE 1, reference numeral lit) indicates generally the relay assembly of the present invention, the relay to being secured to a stationary frame member 11 forming part of the washing machine, in spaced relation to a rotatable basket 12 arranged to rotate along a vertical axis. A contact arm 13 forming part of the relay assembly 10 is located in spaced relation to the basket 12 under normal operating conditions. When, however, the load in the basket is unbalanced suiiiciently to create a condition of dynamic unbalance, the basket 12 may begin to rotate eccentrically in which case the periphery of the basket 12 will contact the contact arm 13 and energize the relay, as explained in succeeding portions of this specification.

The supporting frame for the relay assembly may consist of a shell composed of a sheet metal stamping and including a rear wall 14, and spaced opposed walls 16 and E7. The contact arm 13, which may be conveniently composed of plastic or the like is supported between the opposed walls 16 and 17 by providing upstanding brackets it from the walls 16 and 17, respectively, to thereby confine the contact arm therebetween.

Mounted on the rear wall 14- is a relay coil assembly including a magntizable core 1? and a coil 21 wound about the core. The magnetizable core 19 is arranged to attract a ferromagnetic armature 22. The armature is adjustably spaced from the actuating arm 13 by an adjusting screw 23 extending through a boss 24 formed in the actuating arm 13. The armature 22 has an integral depending portion 25 struck therefrom resting on an insulating button 27 seated along a resilient switch arm 28. The resilience of the arm 23 is sufiicient to normally urge the armature 22. against the adjusting screw 23 and out of contact with the-magnetizable core 19 of the relay assembly.

The resilient switch arm 255 carries a contact 29 at its upper end which is arranged to engage a Z-shaped end portion 31 of a switch arm 32. A third switch arm 33 has a contact 34 normally abutting a similar contact 36 formed on the switch arm 32.

in the normal condition of the device, that is, when the basket i2 is out of contact with the actuating arm 13, the armature 22 is spaced from the core 19, and the contacts 3 and 2 5 are closed. As illustrated in MG- URE 4, the line voltage appearing between a pair of terminals 3? and 33 is thus applied through conductors 39 and 41 to the washing machine. A pair of terminals 42 are provided to incorporate this switch into the energizing line voltage circuit. When, however, there is an unbalanced load in the basket 12, causing an eccentric rotation of the basket sufiicient to engage the actuating t3, the movement of the armature 22 causes the contact 7-9 to come into electrical contact with the end portion 31 of the switch arm 32. This contact then supplied the energizing voltage across the coil 21, as illustrated in FIGURE 3 so that the armature 2?; is attracted to the core 19 immediately after this circuit is completed, the resulting movement of the switch arm 32 causes the contacts 34 and 36 to separate, thereby removing the energizing voltage from the washing machine while retaining the relay energized.

The armature 22 is preferably of sufl'icient mass and width to cause a substantial chattering when the alternating current energizing voltage is applied across the coil 21. This audible signal thereupon warns the operator that the line voltage has been removed from the machine because of an unbalanced load. Upon readjustment of the load within the basket 12, the basket 12 will be disengaged from the actuating arm 13, thereby terminating the energizing of the coil 21 and reapplying the line voltage to the washing machine circuits.

It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.

W e claim as our invention:

1. An assembly for indicating a condition of unbalance in a vibratory machine comprising (a) a support frame,

(21) a magnetizable core carried by said support frame (a) a coil wound about said core,

(68) an armature having one end held by said support frame and its opposite end disposed in confronting relation to siad core in suiiiciently close proximity to be attracted by said core upon energization of said coil,

(e) a first switch arm carried by said support frame and resiliently biasing said opposite end portion of said armature away from said core,

(7) a second switch arm carried by said support frame in close proximity to said first switch arm,

(g) a third switch arm carried by said support frame and in electrical contact with said second switch arm to provide a normally closed switch therewith, and

(h) an actuating arm abutting said armature and positioned to move said armature into closer proximity to said core,

said first switch arm being positioned to open said normally closed switch when said actuating arm moves said armature into closer proximity to said core.

2. The assembly of claim 1 which further includes a threaded means extending between said actuating arm and said armature for adjustably positioning the spacing therebetween.

References Cited by the Examiner UNITED STATES PATENTS 4 3/57 Worst ZOO-61.45 11/57 Zimmer ZOO-87 12/58 Bonnell et a1 ZOO-61.45 7/59 Heoel ZOO-61.45 7/59 Blum ZOO-61.45 12/ 60 Hardway 200-61.45 7/61 Murphy 200-87 5/ 63 Murphy ZOO-61.45 12/63 Davis ZOO-87 FOREIGN PATENTS 8/26 Great Britain. 10/03 France.

15 BERNARD A. GILHEANY, Primary Examiner.

MAX L. LEVY, ROBERT K. SCHAEFER, Examiner's. 

1. AN ASSEMBLY FOR INDICATING A CONDITION OF UNBALANCE IN A VIBRATORY MACHINE COMPRISING (A) A SUPPORT FRAME, (B) A MAGNETIZABLE CORE CARRIED BY SAID SUPPORT FRAME (C) A COIL WOUND ABOUT SAID CORE, (D) AN ARMATURE HAVING ONE END HELD BY SAID SUPPORT FRAME AND ITS OPPOSITE END DISPOSED IN CONFRONTING RELATION TO SAID CORE IN SUFFICIENTLY CLOSE PROXIMITY TO BE ATTRACTED BY SAID CORE UPON ENERGIZATION OF SAID COIL, (E) A FIRST SWITCH ARM CARRIED BY SAID SUPPORT FRAME AND RESILIENTLY BIASING SAID OPPOSITE END PORTION OF SAID ARMATURE AWAY FROM SAID CORE, (F) A SECOND SWITCH ARM CARRIED BY SAID SUPPORT FRAME IN CLOSE PROXIMITY TO SAID FIRST SWITCH ARM, (G) A THIRD SWITCH ARM CARRIED BY SAID SUPPORT FRAME AND IN ELECTRICAL CONTACT WITH SAID SECOND SWITCH ARM TO PROVIDE A NORMALLY CLOSED SWITCH THEREWITH, AND (H) AN ACTUATING ARM ABUTTING SAID ARMATURE AND POSITIONED TO MOVE SAID ARMATURE INTO CLOSER PROXIMITY TO SAID CORE, SAID FIRST SWITCH ARM BEING POSITIONED TO OPEN SAID NORMALLY CLOSED SWITCH WHEN SAID ACTUATING ARM MOVES SAID ARMATURE INTO CLOSER PROXIMITY TO SAID CORE. 